How to use LLVM coverage for for C++
See https://longhanks.github.io/cpp-llvm-coverage
The coverage data is generated using LLVM's Source-based Code Coverage.
The generated HTML output is produced by Chromium's coverage.py (see Code Coverage in Chromium).
llvm-profdata and llvm-cov are downloaded from Chromium (Linux x64, Mac).
The tests are written using Catch2.